首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
A Canadian researcher has discovered that sound travels 【21】______ air more than one-half kilometer an hour slower than had b
A Canadian researcher has discovered that sound travels 【21】______ air more than one-half kilometer an hour slower than had b
admin
2010-07-06
85
问题
A Canadian researcher has discovered that sound travels 【21】______ air more than one-half kilometer an hour slower than had been believed. The discovery has surprised many engineers and scientists who learned they had been 【22】______ the wrong speed of sound for many years.
The speed of sound in air had been【23】______ to be three-hundred-thirty-one-point-two-nine meters a second. But Doctor George Wong found, 【24】______ accident, that the speed of sound is only three-hundred-thirty-one-point-one-three meters a second. That is a difference of about sixteen centimeters a second.
Doctor Wong is a member of the National Research Council of Canada. He was studying ways to 【25】______ exactly the sound created by microph ones. One of his experiments 【26】______ a number he could use to find the speed of sound. He was 【27】______ to learn that the speed of sound was slower than scientists had thought.
To explain the difference, Doctor Wong spent eighteen months 【28】______ past test research on the speed of sound. He finally found the 【29】______ of the difference. It was a mathematics mistake 【30】______ in Nineteen-Forty-Two by physicist H-C Hardy.
Doctor Wong’s 【31】______ does not mean a big change for the science of sound. This is 【32】______ Doctor Hardy and Doctor Wong measured the speed of sound for what is called" standard air".
Standard air exists only 【33】______ thought. It is a way for scientists to agree 【34】______ the same speed of sound. 【35】______ the air around us, standard air always has a temperature of zero degrees Celsius and the same atmospheric pressure 【36】______ the air at sea level. Standard air always has same amounts of nitrogen, oxygen, carbon dioxide and 【37】______ gases. And in standard air, the speed of sound does not change.
The change in the new speed of sound is 【38】______ small to affect the work of most sound scientists and engineers. But scientists say Doctor Wong’s discovery may 【39】______ improve instruments 【40】______ use the speed of sound to measure very short distances.
【35】
选项
A、Since
B、Like
C、For
D、Unlike
答案
D
解析
本句意为“和我们周围的空气不同,标准空气要保持在零摄氏度,并且要有与海平面空气相同的气压。”故应选D 。
转载请注明原文地址:https://kaotiyun.com/show/XyDd777K
本试题收录于:
公共英语四级笔试题库公共英语(PETS)分类
0
公共英语四级笔试
公共英语(PETS)
相关试题推荐
Itwashardtopicturethesemi-opaquemilkinShrekI.
Withthewidespreadcomputers,thereisanincreaseinthenumberofpeoplemakinguseofInternet.SomepeoplebelievethatInt
Supermarketshoppershaveneverbeenmorespoiltforchoice.Butjustwhenwethoughttraditionalsystemsofselectivefarmingh
Accordingtothespeaker,whatareconveniencegoods?
Accordingtothespeaker,whatareconveniencegoods?
Duetohistoricalreasons,peopleintheCzechRepubliclacked________.IvoJupa’sjobusedtofocusoncollectingdonationsfr
WhoearnslessintheUnitedStatesthanthoseinmanyindustrializedcountries?Howmanytimesdidanexperiencedteacherint
Morethan30,000driversandpassengerswhositinthefrontofthevehiclesarekilledorseriouslyinjuredeachyear.Atasp
Duringtheearlyperiodoftheearth’shistory,theweatheronearthapparentlyfluctuatedbetweenbrightsunandshowers.Inr
Healthexpertshavediscoveredthataddinglow-calorievegetablebrothtothestartofamealcanactuallyhelpto______.
随机试题
在Windows中,快速格式化只删除磁盘上的文件,但不检查磁盘的坏扇区;完全格式化会删除磁盘上的全部文件并在检查磁盘后将坏扇区标注出来。()
Akingonce【C1】______seriouslyill.Hisdoctorsandwisementriedcure【C2】______cure.Butnothing【C3】______.Theywerereadyto
治疗麻疹初热期的首选方剂是()治疗麻疹出疹期的首选方剂是()
与传导下肢本体感觉相关的结构是
阅读《论语十则》,回答问题。1.子曰:“学而时习之,不亦说()乎?有朋自远方来,不亦乐乎?人不知而不愠,不亦君子乎?”(《学而》)2.曾子曰:“吾日三省()吾身:为人谋而不忠乎?与朋友交而不信乎?传不习乎?”(《学而》)3.子曰:“温故而知新,可以为
她(路瓦栽夫人)也是一个美丽动人的姑娘,好像由于命运的差错,生在一个小职员的家里。她没有陪嫁的资产,也没有什么法子让一个有钱的体面人认识她,了解她,爱她,娶她;最后只得跟教育部的一个小书记结了婚。“她也是一个美丽动人的姑娘,好像由于命运的差错,生在
甲、乙、丙三人生产一批零件共用时8天,其中甲每天的工作效率等于乙、丙两人之和,丙的工作效率等于甲、乙之和的1/5。已知乙每天可生产零件40个,那么这批零件共有多少个?
求∫0πe-xsinnxdx.
Whichhotelhasnobreakfastservice?
【B1】【B2】
最新回复
(
0
)